My -7 project had about 90% of the work done with a 20 gal airless compressor, that sat just outside the workroom door. A little loud, but obviously bearable. The only times it was an issue is trying to use an air grinder, which will tax all but the largest compressors.
So, if money *is* an object, don't worry too much about going cheap.
I do have a very large 'traditional' compressor now, & it came in handy last night when a friend came over & sprayed the interior for me. I was geared up for Rustoleum Pro, but who could resist free labor.
The rest of this is slightly off topic, but might be interesting. He's a pro painter (owns a couple of body shops) and sprayed an automotive polyurethane with no special special setup, just drain the tank & leave the drain valve to bleed slightly. He sprayed in my open hangar, with it raining outside. He said that he wanted to paint with it raining & fairly cool to keep the bugs & dust down. Pretty much everything I would have tried to avoid if I was painting. The paint looks great, with just a few dust issues when the wind came up a bit more than we planned for.
This really has been an education....
Charlie